Question

y = x³+ 3 x + x³x

Answer 1

$y=x^3+3x+x^3x$

$\implies y=x^4+x^3+3x$

Slope at any point $(y_1,x_1)$ is given by,

$(\frac{dy}{dx})_{(x_1,y_1)}=\frac{d(x^4+x^3+3x)}{dx}_{(x_1,y_1)}$

$=(4x^3+3x^2+3)_{x_1,y_1}$

$=4x_1^3+3x_1^2+3$